From Magento 2.3, Core modules use the declarative schema approach rather than setup upgrade scripts. This is the new recommended approach for Magento versions 2.3 and upper version.
All the InstallData and UpgrageData will be replaced by Data Patch Versioning.
Now you have to create Setup/Patch/Data folder and create the class file for create/update attribute or add sample data in Magento.
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